Once a project is past the prototype stage there is no need to use a complete Arduino, even with the ever decreasing cost of Arduino compatibles and the availability of cut down versions such as the Arduino Nano and Mini it’s still overkill for a lot of uses. Fortunately it is very easy to build your own Arduino compatible circuit around the ATmega microcontroller and it will only cost you a few pounds; with some good deals on bulk components and by flashing the Arduino bootloader yourself you could do this for as little as a fiver.

You will need a piece of stripboard at least 20 holes across by 19 strips or 14 holes across if on board programming and reset button aren’t required.

If you don’t need the on board reset button you can leave that out and if you don’t need on board programming you can omit the 6 pin header and 100nF capacitor. If you aren’t using both the reset button and the FTDI connection then you can also omit the 10K resistor. The 1N4001 diode isn’t strictly necessary either, it’s just there for reverse polarity protection.

You can use the ATmega168 (half the Flash/EEPROM/SRAM of the ATmega328) if that is all you require, either way the Atmel AVR will require the Arduino bootloader flashed to it before you can upload a sketch to it, you can either buy one with it preloaded or use another Arduino to burn it yourself. If you want to buy one preloaded you can get the ATmega328 on eBay here together with the required crystal and the 22pF loading caps.

The build

Break the tracks on the copper side of the board where indicated with the red crosses and solder in the components, if you haven’t used stripboard before see this page for an explanation of how to use it. Make sure the socket for the ATmega chip is installed with the notch at the top and the LM7805 voltage regulator is installed with the metal strip at the right hand side. The 1N4001 diode needs to be installed with the side marked with a band at the top and the two electrolytic capacitors also need to be installed the right way round (note the + signs in the diagram above) the positive lead should be longer and there is usually a stripe on the canister marking the negative side. Install the tactile switch with the legs on the sides so that it joins the top and bottom strips when pressed. The other components can all go in either way round.

Power Connections

You can connect power to the VIN and ground on the right, 7 to 9VDC will be fine as is but I’d put a heatsink on the LM7805 voltage regulator if using 12V. You can also power it via USB from the FTDI connection but make sure that the external power (VIN) isn’t connected at the same time; if you want to have both connected you can disable the FTDI power completely by omitting the link shown in blue next to the 6 pin header.

I/O connections

I’ve marked the locations of the digital and analogue lines on the layout above (note they are in a different layout to the Arduino board) but have not included headers in the parts list as normally you would be connecting directly to the board once you are past the prototype stage.

Programming

Loading a sketch can be done by connecting a 5V FTDI board or cable to the 6 pin header or by temporarily transferring the ATmega chip into another Arduino for programming. A good USB FTDI cable is available on eBay here, make sure you get the 5V version.

I just found your article and decided to build one of these for my next arduino project. The processor part works well, as would be expected. I however can’t upload a sketch to the atmega 328. I am using the Sparkfun FTDI breakout board and I made sure the pinout was correct. I had to swap Rx and Tx. I’m not sure what could be going on, any ideas would be appreciated.

The message I am getting is: avrdude: stk500_getsync(): not in sync: resp=0x00

I figured out what the problem is and am now able to upload sketches. I tied the cts line on the FTDI breakout board to gnd and it works like a charm. I found it by reading the Sparkfun writeup on the breakout board. Hope this helps someone in the future.

Hi.I have built with some mods.The regulator capacitors are 10 uf ,also added resistor +led on pin 13(like the original arduino uno board).Uploaded the blink sketch using the usb2serial light adapter and everything worked fine!Uploaded some other example sketches and everything wend good.BUT when i try the lcd library uploading the “Hello world” example, the 13 pin led flashes continously (like continous resets) and nothing happens UNTIL i start the serial monitor and…everything works!! Stopping the serial monitor jams everything .Any ideas?
Thanks anyway for the nice design!
(I select the uno board from the arduino IDE running on XP windows machine)

I have built your veroduino exactly like the diagram and circuit. I only added a led to pin 13 and for power. My problem is that I have uploaded a pov scetch but the leds seem to be flash slower and dimmer than if it was on the UNO. Needless to say that the pov does not work as it should. Why do you think its doing this.

Hello Nathan, and very very thanks for your usefully tutorials.
I have some ATMEL 168 and some 328, and soon I’m gonna do my first veroboard, thanks to your posts.

’cause I’m REALLY newbie in electronic stuff (but I’m learning, hopefully fast), I don’t understand why is there a need to make cuts on the rear of veroboard. Can I ask you why cut tracks? Are not already separated?
Thanks in advance and really sorry for the newbie question 🙂

@Kevin, That’s puzzling, it shouldn’t be any different, what are you powering it with?

@Piero, The strips are separated but if you want to put components inline with a strip you need to break it otherwise there would be a short. For example if you look at where the 328 chip is if the tracks were not broken underneath it then all the pins on the left would be joined to those on the right – not what we want.

On stripboard (veroboard) there are copper strips on the bottom of the board that you need to cut in certain places where you don’t want components on the same strip to be connected together. You can get proper tools for this but an 1/8″ drill bit will do in a push. You put it in the hole on the copper side and twist to break the copper so it is no longer joined.

thank you nathan for such a quick reply to my questions..i have another doubt that should i have to check before i insert the atmega 328 chipset to the controller??if is then can u please tell me how to check it.i am very new to it so please dont mind..please help me!!!!

thank u nathan and peiro for the help!!!but now i need help again…today i had completed the circuit but now when i connect to the laptop via usbasp nothing is working and the led is not glowing…..but when i connect it to the 7-9v supply the microprocessor gets hot…..what shall i do????what is the problem??did i done any mistake??please help me nathan and peiro!!!!!!!!!!!!

nathan i have connected the usbasp as follows
SCK to pin13 on atmega
MISO to pin12 on atmega
MOSI to pin11 on atmega
RST to reset on the Arduino (pin one on the ATmega).
Power pin2 on atmega
Ground pin3 on atmega….i find the led dosnt glow…but while kept it connected the microprocessor gets hot as i plug 7-9v power suppy to it…

Hi,
I notice that the link given by me has changed since I published it.
Go to website and query the webmaster if possible for information about the article that used to be at that link.
Sorry for the hiccup!

I need a 5v power source for the project. Can I draw power from the board (if yes where would be the right place on the board to draw it from) or should i power the project with a separate power supply?

Thank you. This is very nice and complete. I appreciate the reference links. I am building a crazy project which will be a modernised version of the old plastic Digicomp 1 I had as a lad. There will be a big array of switches that I am going to try to charlieplex into the Arduino. Several leds, etc. When I have it working with the Arduino I will give it one of its own using your nifty build right on the same stripboard. This is going to be fun. After all that’s what it’s all about.